"It's the doing of something that results in distortion, mutilation or alteration of a work that's somehow prejudicial to the creator's honour or reputation," said Kimberlee Weatherall, a professor of law at the University of Sydney.

"They are meant to protect that connection that exists between a creator and the work they have created ... That really personal, 'I put my heart and soul into this, it represents in some way a part of me, and I have a right to protect that from incursion'."

The definition of derogatory is quite broad, experts say.

"Looking at the law, this could be the kind of thing that could be prejudicial to an author's honour or reputation," Professor Weatherall said.

Is legal action against Bernardi likely?

"I went to a great deal of trouble to construct this song to be well above any kind of politics," he said.

"So to have it associated with any politics at all is, as far as I'm concerned, compromising the integrity of the song."

He added: "We've requested that he takes it down and I'm still waiting for the publishers and the record company to get back to me on how they've gone with that."

Court action would be expensive, and any kind of reputational damage — which you'd need to show to win any money — would be hard to prove, given the artists themselves have publicly said they don't agree with Mr Bernardi and his politics.

"There was a very interesting discussion in that case about whether political associations, with say a terrorist organisation or a racist party, might constitute debasement," Matthew Rimmer, a professor of intellectual property and innovation at QUT's law school, said.